Henry, JOSEPH

Henry, JOSEPH, physicist, was born either in 1797 or 1799, in Albany, New York. There, while apprenticed to a watchmaker, he took up the study of science, and earned means to carry him through the course at the academy, in which institution he became instructor in Mathematics in 1826. In 1832 he was called to the chair of Natural Philosophy at Princeton; in 1846 he was elected the first secretary of the Smithsonian Institution, and removed to Washington, where he died, 13th May 1878. Apart from his great services to the Smithsonian Institution, with Henry's name are associated the discovery of a relation between the number of coils of wire round the electro-magnet and the construction of the battery to work it, which prepared the way for Morse's invention, in which his principles were applied to make the instrument effective at a distance; the discovery of a singular form of electrical induction; researches in meteorology and acoustics; and the establishment of the national lighthouse board, of which he was chairman from 1871 until his death. He was LL.D. of Union (1829) and Harvard (1851), and a member of many scientific societies in America and Europe. Of his numerous papers 2 vols. were published in 1886; and a Memorial was published by order of congress in 1880.